Various approaches have been taken in efforts to convert black-and-white motion pictures to provide a color presentation. The desire for a practical and economic process of attaining that conversion, stems from two basic considerations. First, a large number of black-and-white motion pictures (particularly classic films) would have considerably-increased audience appeal, and thus value, if they were converted to provide a color display. Second, in some situations it may be economical to produce a black-and-white motion picture film, film-sequence, or television commercial, then subsequently color the film. That approach is feasible to avoid the significantly-increased costs attendant color production. It should be appreciated in that regard, that the increased cost of color photographic film is compounded by the additional requirements of costumes, special makeup, lighting, special sets and color-related props.
One method of adding color to a black-and-white motion picture is disclosed in U.S. Pat. No. 2,127,829 (O'Brien). Essentially, as disclosed in that patent, a black-and-white image from a motion picture frame is projected through a translucent screen that is composed of accurately cut and fitted color filters. The resulting colored light image is then photographed with color-sensitive film. Generally, the system was proposed for imparting color to still background objects which could then be matingly merged with images of foreground objects and actors.
In utilizing the process of the above-referenced O'Brien patent, a separate color filter component member has to be accurately cut and fitted into the complex image filter so as to coincide with each element of the background. Accordingly, the system was never contemplated for use in converting a completed black-and-white motion picture film with actors and foreground detail to color, but rather was only intended to provide an artificially-colored background, e.g. sky, sea, landscape and so on, to be merged with a foreground scene and detail (as on a sound stage) to thereby complete the motion picture film.
Another previously-proposed method of making colored pictures is disclosed in U.S. Pat. No. 2,927,857 (Pohl). Generally, according to the Pohl process a black-and-white image is projected onto a sheet of paper to which color is applied. Subsequently, color-sensitive film is contact-exposed in mating engagement with the black-and-white film while receiving the color-blocked image from the paper, through a lens. To accomplish foreground details, in color by the Pohl process, a series of transparent sheets are superimposed over the background color format.
Generally, the direct-contact film arrangement of the Pohl system presents certain inherent difficulties as necessitating that the color image pass through the black-and-white film in exposing the color-sensitive film. Emulsion problems and inter-surface reflections are also attendant the mating arrangement of the two films. Furthermore, in practicing the Pohl process, each film sequence requires a minimum of one background rendering and a transparency for each frame carrying the foreground objects. Accordingly, the limitations of the system are apparent.
A variety of processes have been utilized in the production of animated cartoons which may be deemed somewhat related or pertinent to the conversion of black-and-white film to a color medium. Summarily, for one reason or another, such techniques are not fully applicable to provide an economical solution to the problem. Specifically, for example, U.S. Pat. No. 1,715,230 (Gilmartin) discloses the use of an opaque cartoon character that is positioned between a projected image and a camera while U.S. Pat. No. 2,450,017 (Place) discloses a technique in which opaque foreground images are super-imposed on background images to be photographed in combination. These techniques are typical and neither is particularly applicable to, or of assistance in solving the problem contemplated by the present invention.
In general, the present invention is directed to a system for converting a black-and-white motion picture film to a colored motion picture film (frame-by-frame) by projecting the black-and-white image from a single frame onto a work surface and applying color to the work surface at selected areas of the projected image to provide a first composite of applied color and black-and-white image, then photographing the composite with color-sensitive film to register the conversion for that frame. Subsequently, the next frame in a sequence is projected from the black-and-white film onto the work surface which is preserved in registration therewith and modified to provide the next composite which is photographed with that frame to register the next color frame.